(1) Field of the Invention
The present invention relates to a transmission equipment, and more particularly to a basic architecture of a transmission equipment for effectively realizing data back-up, program down-loading, diagnosis of respective functions, The transmission equipment relating to the present invention is located close to subscriber terminals or to an exchange, for converting analog signals to digital signals or vise versa. The present invention also relates to a memory updating system for a integrated state management device (or, in other words, a center management device) in the transmission equipment, which allows maintenance operation, such as version up operation for a unit without requiring modification of the integrated state management device.
(2) Description of the Related Art
In recent years, telecommunication technologies have progressed very quickly for providing more and more options for subscribers. Such progress in technologies of communication naturally requires more functions or performances for transmission system. Namely, according to the increase of functions or performance of the transmission equipment in recent years, there is a tendency to replace the construction solely formed by hardware in the prior art with CPU. Therefore, reliance for the software which controls CPU is increased. As a result, the influences of bug in the software, version up of the software by adding a new function, destruction of data necessary for running the software, etc., on service to customers is increased. Therefore, a countermeasure to suppress the influences has been required. This requires that the transmission equipment has functions of data back-up, program down-loading, self-diagnosis.
In the meanwhile, it is the typical conventional custom that, in order to realize higher performance, each unit in the transmission equipment includes a CPU (central processing unit) and a program, and data is managed independently by the unit.
In such conventional system, various drawbacks are encountered. For example, even when data back-up is performed in the same unit, if the unit goes breakdown and is necessary to be replaced, the back-up data are also lost so that back-up becomes meaningless. Therefore, for back-up, separate unit has to be provided. Namely, when data back-up, program down-loading, self-diagnosis is to be realized in such architecture, it becomes necessary to establish dual system for each unit. This clearly cause a higher cost for the facilities and requires a larger size of the system. Furthermore, it may results in degradation of installation efficiency of the transmission equipment and create a problem that the above-mentioned function, such as data back-up, cannot be practically realized.
On the other hand, in the modern telephone network system, it is a trend to have a integrated state management device for integrally managing data in the units in the transmission equipment, for higher efficiency of maintenance operation. In such integrated state management device, according to progress of the technologies in the transmission equipments and to increasing of data amount for state management, higher speed of data processing and effective use of memories have been strongly required.
In such integrated state management device, when the version up of the transmission equipment is effected by adding a memory board, it becomes essential to make the state information in the memory of the integrated state management device and the state information in the memory of the memory board are consistent with each other. Therefore, checking operation for check SUM becomes necessary.
In this case, if the interface between the integrated state management device and the memory board allows only read/write functions, the unit will perform reading operation to read out the memory content of the integrated state management device and to perform check of the check SUM therein. Typically, processing in the unit is performed to sequentially read out predetermined size Of memory contents in the memory of the integrated state management device. As set forth above, since it is essential that the memory contents in the unit and that in the integrated state management device must be consistent from each other, such process of reading data segments and performing checking of check SUM has to be performed regularly or continuously. For plurality units, the integrated state management device sequentially issues sequence master right for respective unit in order by polling. Therefore, number of sequences corresponding to the number of the units in the transmission equipment becomes necessary. When number of units is increased for version up, the sequences between the integrated state management device and units are naturally increased. This clearly causes delay of the process time. In addition, in case that the memory capacities in respective units are not sufficient, number of sequences should be further increased to cause further delay in the process.
On the other hand, when the interface between the integrated state management device and the units allows functions other than read/write function, an addition of check SUM calculation process request command (CMD) is required to the integrated state management device from the unit, associated with increasing or modification of the functions. Also, when other function is required, the addition of the corresponding command becomes necessary. In such case, the integrated state management device is required to be provided the decoding means for the new commands as well as programs necessary for performing the new commands. This causes necessity of modification of the integrated state management device.